Q: Splitting vector into x and y components.
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I have struck a problem within the aspects of simple middle school geometry. I'll just cut to the case.
Visual exmaple of problem
We have a triangle of any size or form. We know angles A, B and C. We have a vector, v along one of the triangles sides. We know the magnitude of vector v. We have a smaller triangle representing the x and y components. We do not know the angles of the smaller triangle, other than it is a right angled triangle. Keep in mind that the original triangle can be of any size or form, so in the case of the picture, extending the vector triangle to get one of the angles is not an option. Is it possible to acquire the x and y components? If so, is there any general formula to achieve this?
Sorry for the horrible picture. Any help is highly appreciated.
Edit: I forgot to inform that we also know the x and y coordinates of the original triangles corners.
geometry vectors triangle
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up vote
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down vote
favorite
I have struck a problem within the aspects of simple middle school geometry. I'll just cut to the case.
Visual exmaple of problem
We have a triangle of any size or form. We know angles A, B and C. We have a vector, v along one of the triangles sides. We know the magnitude of vector v. We have a smaller triangle representing the x and y components. We do not know the angles of the smaller triangle, other than it is a right angled triangle. Keep in mind that the original triangle can be of any size or form, so in the case of the picture, extending the vector triangle to get one of the angles is not an option. Is it possible to acquire the x and y components? If so, is there any general formula to achieve this?
Sorry for the horrible picture. Any help is highly appreciated.
Edit: I forgot to inform that we also know the x and y coordinates of the original triangles corners.
geometry vectors triangle
It's not possible as the orientation of the original triangle is not known. If you can rotate the figure in such a way that vector is parallel to axis $x$ or $y$, you solved your problem.
– Vasya
Nov 15 at 15:41
add a comment |
up vote
0
down vote
favorite
up vote
0
down vote
favorite
I have struck a problem within the aspects of simple middle school geometry. I'll just cut to the case.
Visual exmaple of problem
We have a triangle of any size or form. We know angles A, B and C. We have a vector, v along one of the triangles sides. We know the magnitude of vector v. We have a smaller triangle representing the x and y components. We do not know the angles of the smaller triangle, other than it is a right angled triangle. Keep in mind that the original triangle can be of any size or form, so in the case of the picture, extending the vector triangle to get one of the angles is not an option. Is it possible to acquire the x and y components? If so, is there any general formula to achieve this?
Sorry for the horrible picture. Any help is highly appreciated.
Edit: I forgot to inform that we also know the x and y coordinates of the original triangles corners.
geometry vectors triangle
I have struck a problem within the aspects of simple middle school geometry. I'll just cut to the case.
Visual exmaple of problem
We have a triangle of any size or form. We know angles A, B and C. We have a vector, v along one of the triangles sides. We know the magnitude of vector v. We have a smaller triangle representing the x and y components. We do not know the angles of the smaller triangle, other than it is a right angled triangle. Keep in mind that the original triangle can be of any size or form, so in the case of the picture, extending the vector triangle to get one of the angles is not an option. Is it possible to acquire the x and y components? If so, is there any general formula to achieve this?
Sorry for the horrible picture. Any help is highly appreciated.
Edit: I forgot to inform that we also know the x and y coordinates of the original triangles corners.
geometry vectors triangle
geometry vectors triangle
edited Nov 15 at 15:48
asked Nov 15 at 15:35
Lukas Knudsen
33
33
It's not possible as the orientation of the original triangle is not known. If you can rotate the figure in such a way that vector is parallel to axis $x$ or $y$, you solved your problem.
– Vasya
Nov 15 at 15:41
add a comment |
It's not possible as the orientation of the original triangle is not known. If you can rotate the figure in such a way that vector is parallel to axis $x$ or $y$, you solved your problem.
– Vasya
Nov 15 at 15:41
It's not possible as the orientation of the original triangle is not known. If you can rotate the figure in such a way that vector is parallel to axis $x$ or $y$, you solved your problem.
– Vasya
Nov 15 at 15:41
It's not possible as the orientation of the original triangle is not known. If you can rotate the figure in such a way that vector is parallel to axis $x$ or $y$, you solved your problem.
– Vasya
Nov 15 at 15:41
add a comment |
3 Answers
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OK, your edit makes all the difference in the world. Let $B(x_B,y_B)$ be the start of the vector and $A(x_A,y_A)$ is a vertex on the same side of the triangle where the vector is. Then you can easily find tangent of the vector $m=frac{Y_B-Y_A}{X_B-X_A}$ (beware of division by zero). Then $|x|=frac{1}{sqrt{1+m^2}}v$, $|y|=frac{|m|}{sqrt{1+m^2}}v$ where $v$ is the magnitude of vector $vec{v}$. You can determine whether $x$ and $y$ are positive or negative by finding components of vector $vec{BA}(x_A-x_B,y_A-y_B)$. They will have the same signs.
Thank you so much for the answer. Is your labeling relative to the picture i posted? The math doesn't quite make sense to me. Sorry if it is too much to ask for.
– Lukas Knudsen
Nov 15 at 16:20
@LukasKnudsen: You have not labeled vertices in your picture, I guess you want vector to start at $C$ according to the $angle{C}$ so just replace $B$ with $C$ in my answer. The other vertex remains $A$. The math is basically finding sine and cosine based on tangent.
– Vasya
Nov 15 at 16:32
Thank you for the clarification. Just to make sure I understood it, here's an example. $A( 0, 0 ), B( 10, 5 ), v=5, m=tan^-1(frac{5 - 0}{10 - 0})=26.6, |x|=frac{5}{sqrt{1 + 26.6^2}}=0.188, |y|=frac{26.6 * 5}{sqrt{1 + 26.6^2}}=4.996$. The x and y components seem to be off. Is this correct?
– Lukas Knudsen
Nov 15 at 16:58
@LukasKnudsen: no, $m=frac{5-0}{10-0}=0.5$, $|x|approx 4.47$, $|y| approx 2.236$, $BA(-10,-5)$ so $x=-4.47, y=-2.236$
– Vasya
Nov 15 at 17:12
Ohhh, I see. $m$ is the gradient and I just need to multiply $|x|$ and $|y|$ by the components of the directional vector of $vec{BA}$. Thank you.
– Lukas Knudsen
Nov 15 at 17:18
|
show 1 more comment
up vote
0
down vote
Not from the information provided. In particular, any rotation of the triangle shown would give different $x$ and $y$ values, but the same $A$, $B$, and $C$, so there is no possible function giving $x$ and $y$ in terms of $A$, $B$, and $C$ alone.
add a comment |
up vote
0
down vote
Since you know the coordinates of the vertices, you can ignore the angles. The coordinates of $vec v$ can be found as a proportion of the coordinates of the appropriate edge. For the illustrated case, $$vec v = {|vec v|over|A-C|}(A-C).$$
add a comment |
3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
0
down vote
accepted
OK, your edit makes all the difference in the world. Let $B(x_B,y_B)$ be the start of the vector and $A(x_A,y_A)$ is a vertex on the same side of the triangle where the vector is. Then you can easily find tangent of the vector $m=frac{Y_B-Y_A}{X_B-X_A}$ (beware of division by zero). Then $|x|=frac{1}{sqrt{1+m^2}}v$, $|y|=frac{|m|}{sqrt{1+m^2}}v$ where $v$ is the magnitude of vector $vec{v}$. You can determine whether $x$ and $y$ are positive or negative by finding components of vector $vec{BA}(x_A-x_B,y_A-y_B)$. They will have the same signs.
Thank you so much for the answer. Is your labeling relative to the picture i posted? The math doesn't quite make sense to me. Sorry if it is too much to ask for.
– Lukas Knudsen
Nov 15 at 16:20
@LukasKnudsen: You have not labeled vertices in your picture, I guess you want vector to start at $C$ according to the $angle{C}$ so just replace $B$ with $C$ in my answer. The other vertex remains $A$. The math is basically finding sine and cosine based on tangent.
– Vasya
Nov 15 at 16:32
Thank you for the clarification. Just to make sure I understood it, here's an example. $A( 0, 0 ), B( 10, 5 ), v=5, m=tan^-1(frac{5 - 0}{10 - 0})=26.6, |x|=frac{5}{sqrt{1 + 26.6^2}}=0.188, |y|=frac{26.6 * 5}{sqrt{1 + 26.6^2}}=4.996$. The x and y components seem to be off. Is this correct?
– Lukas Knudsen
Nov 15 at 16:58
@LukasKnudsen: no, $m=frac{5-0}{10-0}=0.5$, $|x|approx 4.47$, $|y| approx 2.236$, $BA(-10,-5)$ so $x=-4.47, y=-2.236$
– Vasya
Nov 15 at 17:12
Ohhh, I see. $m$ is the gradient and I just need to multiply $|x|$ and $|y|$ by the components of the directional vector of $vec{BA}$. Thank you.
– Lukas Knudsen
Nov 15 at 17:18
|
show 1 more comment
up vote
0
down vote
accepted
OK, your edit makes all the difference in the world. Let $B(x_B,y_B)$ be the start of the vector and $A(x_A,y_A)$ is a vertex on the same side of the triangle where the vector is. Then you can easily find tangent of the vector $m=frac{Y_B-Y_A}{X_B-X_A}$ (beware of division by zero). Then $|x|=frac{1}{sqrt{1+m^2}}v$, $|y|=frac{|m|}{sqrt{1+m^2}}v$ where $v$ is the magnitude of vector $vec{v}$. You can determine whether $x$ and $y$ are positive or negative by finding components of vector $vec{BA}(x_A-x_B,y_A-y_B)$. They will have the same signs.
Thank you so much for the answer. Is your labeling relative to the picture i posted? The math doesn't quite make sense to me. Sorry if it is too much to ask for.
– Lukas Knudsen
Nov 15 at 16:20
@LukasKnudsen: You have not labeled vertices in your picture, I guess you want vector to start at $C$ according to the $angle{C}$ so just replace $B$ with $C$ in my answer. The other vertex remains $A$. The math is basically finding sine and cosine based on tangent.
– Vasya
Nov 15 at 16:32
Thank you for the clarification. Just to make sure I understood it, here's an example. $A( 0, 0 ), B( 10, 5 ), v=5, m=tan^-1(frac{5 - 0}{10 - 0})=26.6, |x|=frac{5}{sqrt{1 + 26.6^2}}=0.188, |y|=frac{26.6 * 5}{sqrt{1 + 26.6^2}}=4.996$. The x and y components seem to be off. Is this correct?
– Lukas Knudsen
Nov 15 at 16:58
@LukasKnudsen: no, $m=frac{5-0}{10-0}=0.5$, $|x|approx 4.47$, $|y| approx 2.236$, $BA(-10,-5)$ so $x=-4.47, y=-2.236$
– Vasya
Nov 15 at 17:12
Ohhh, I see. $m$ is the gradient and I just need to multiply $|x|$ and $|y|$ by the components of the directional vector of $vec{BA}$. Thank you.
– Lukas Knudsen
Nov 15 at 17:18
|
show 1 more comment
up vote
0
down vote
accepted
up vote
0
down vote
accepted
OK, your edit makes all the difference in the world. Let $B(x_B,y_B)$ be the start of the vector and $A(x_A,y_A)$ is a vertex on the same side of the triangle where the vector is. Then you can easily find tangent of the vector $m=frac{Y_B-Y_A}{X_B-X_A}$ (beware of division by zero). Then $|x|=frac{1}{sqrt{1+m^2}}v$, $|y|=frac{|m|}{sqrt{1+m^2}}v$ where $v$ is the magnitude of vector $vec{v}$. You can determine whether $x$ and $y$ are positive or negative by finding components of vector $vec{BA}(x_A-x_B,y_A-y_B)$. They will have the same signs.
OK, your edit makes all the difference in the world. Let $B(x_B,y_B)$ be the start of the vector and $A(x_A,y_A)$ is a vertex on the same side of the triangle where the vector is. Then you can easily find tangent of the vector $m=frac{Y_B-Y_A}{X_B-X_A}$ (beware of division by zero). Then $|x|=frac{1}{sqrt{1+m^2}}v$, $|y|=frac{|m|}{sqrt{1+m^2}}v$ where $v$ is the magnitude of vector $vec{v}$. You can determine whether $x$ and $y$ are positive or negative by finding components of vector $vec{BA}(x_A-x_B,y_A-y_B)$. They will have the same signs.
edited Nov 15 at 16:15
answered Nov 15 at 16:09
Vasya
3,2691515
3,2691515
Thank you so much for the answer. Is your labeling relative to the picture i posted? The math doesn't quite make sense to me. Sorry if it is too much to ask for.
– Lukas Knudsen
Nov 15 at 16:20
@LukasKnudsen: You have not labeled vertices in your picture, I guess you want vector to start at $C$ according to the $angle{C}$ so just replace $B$ with $C$ in my answer. The other vertex remains $A$. The math is basically finding sine and cosine based on tangent.
– Vasya
Nov 15 at 16:32
Thank you for the clarification. Just to make sure I understood it, here's an example. $A( 0, 0 ), B( 10, 5 ), v=5, m=tan^-1(frac{5 - 0}{10 - 0})=26.6, |x|=frac{5}{sqrt{1 + 26.6^2}}=0.188, |y|=frac{26.6 * 5}{sqrt{1 + 26.6^2}}=4.996$. The x and y components seem to be off. Is this correct?
– Lukas Knudsen
Nov 15 at 16:58
@LukasKnudsen: no, $m=frac{5-0}{10-0}=0.5$, $|x|approx 4.47$, $|y| approx 2.236$, $BA(-10,-5)$ so $x=-4.47, y=-2.236$
– Vasya
Nov 15 at 17:12
Ohhh, I see. $m$ is the gradient and I just need to multiply $|x|$ and $|y|$ by the components of the directional vector of $vec{BA}$. Thank you.
– Lukas Knudsen
Nov 15 at 17:18
|
show 1 more comment
Thank you so much for the answer. Is your labeling relative to the picture i posted? The math doesn't quite make sense to me. Sorry if it is too much to ask for.
– Lukas Knudsen
Nov 15 at 16:20
@LukasKnudsen: You have not labeled vertices in your picture, I guess you want vector to start at $C$ according to the $angle{C}$ so just replace $B$ with $C$ in my answer. The other vertex remains $A$. The math is basically finding sine and cosine based on tangent.
– Vasya
Nov 15 at 16:32
Thank you for the clarification. Just to make sure I understood it, here's an example. $A( 0, 0 ), B( 10, 5 ), v=5, m=tan^-1(frac{5 - 0}{10 - 0})=26.6, |x|=frac{5}{sqrt{1 + 26.6^2}}=0.188, |y|=frac{26.6 * 5}{sqrt{1 + 26.6^2}}=4.996$. The x and y components seem to be off. Is this correct?
– Lukas Knudsen
Nov 15 at 16:58
@LukasKnudsen: no, $m=frac{5-0}{10-0}=0.5$, $|x|approx 4.47$, $|y| approx 2.236$, $BA(-10,-5)$ so $x=-4.47, y=-2.236$
– Vasya
Nov 15 at 17:12
Ohhh, I see. $m$ is the gradient and I just need to multiply $|x|$ and $|y|$ by the components of the directional vector of $vec{BA}$. Thank you.
– Lukas Knudsen
Nov 15 at 17:18
Thank you so much for the answer. Is your labeling relative to the picture i posted? The math doesn't quite make sense to me. Sorry if it is too much to ask for.
– Lukas Knudsen
Nov 15 at 16:20
Thank you so much for the answer. Is your labeling relative to the picture i posted? The math doesn't quite make sense to me. Sorry if it is too much to ask for.
– Lukas Knudsen
Nov 15 at 16:20
@LukasKnudsen: You have not labeled vertices in your picture, I guess you want vector to start at $C$ according to the $angle{C}$ so just replace $B$ with $C$ in my answer. The other vertex remains $A$. The math is basically finding sine and cosine based on tangent.
– Vasya
Nov 15 at 16:32
@LukasKnudsen: You have not labeled vertices in your picture, I guess you want vector to start at $C$ according to the $angle{C}$ so just replace $B$ with $C$ in my answer. The other vertex remains $A$. The math is basically finding sine and cosine based on tangent.
– Vasya
Nov 15 at 16:32
Thank you for the clarification. Just to make sure I understood it, here's an example. $A( 0, 0 ), B( 10, 5 ), v=5, m=tan^-1(frac{5 - 0}{10 - 0})=26.6, |x|=frac{5}{sqrt{1 + 26.6^2}}=0.188, |y|=frac{26.6 * 5}{sqrt{1 + 26.6^2}}=4.996$. The x and y components seem to be off. Is this correct?
– Lukas Knudsen
Nov 15 at 16:58
Thank you for the clarification. Just to make sure I understood it, here's an example. $A( 0, 0 ), B( 10, 5 ), v=5, m=tan^-1(frac{5 - 0}{10 - 0})=26.6, |x|=frac{5}{sqrt{1 + 26.6^2}}=0.188, |y|=frac{26.6 * 5}{sqrt{1 + 26.6^2}}=4.996$. The x and y components seem to be off. Is this correct?
– Lukas Knudsen
Nov 15 at 16:58
@LukasKnudsen: no, $m=frac{5-0}{10-0}=0.5$, $|x|approx 4.47$, $|y| approx 2.236$, $BA(-10,-5)$ so $x=-4.47, y=-2.236$
– Vasya
Nov 15 at 17:12
@LukasKnudsen: no, $m=frac{5-0}{10-0}=0.5$, $|x|approx 4.47$, $|y| approx 2.236$, $BA(-10,-5)$ so $x=-4.47, y=-2.236$
– Vasya
Nov 15 at 17:12
Ohhh, I see. $m$ is the gradient and I just need to multiply $|x|$ and $|y|$ by the components of the directional vector of $vec{BA}$. Thank you.
– Lukas Knudsen
Nov 15 at 17:18
Ohhh, I see. $m$ is the gradient and I just need to multiply $|x|$ and $|y|$ by the components of the directional vector of $vec{BA}$. Thank you.
– Lukas Knudsen
Nov 15 at 17:18
|
show 1 more comment
up vote
0
down vote
Not from the information provided. In particular, any rotation of the triangle shown would give different $x$ and $y$ values, but the same $A$, $B$, and $C$, so there is no possible function giving $x$ and $y$ in terms of $A$, $B$, and $C$ alone.
add a comment |
up vote
0
down vote
Not from the information provided. In particular, any rotation of the triangle shown would give different $x$ and $y$ values, but the same $A$, $B$, and $C$, so there is no possible function giving $x$ and $y$ in terms of $A$, $B$, and $C$ alone.
add a comment |
up vote
0
down vote
up vote
0
down vote
Not from the information provided. In particular, any rotation of the triangle shown would give different $x$ and $y$ values, but the same $A$, $B$, and $C$, so there is no possible function giving $x$ and $y$ in terms of $A$, $B$, and $C$ alone.
Not from the information provided. In particular, any rotation of the triangle shown would give different $x$ and $y$ values, but the same $A$, $B$, and $C$, so there is no possible function giving $x$ and $y$ in terms of $A$, $B$, and $C$ alone.
answered Nov 15 at 15:40
user3482749
1,709411
1,709411
add a comment |
add a comment |
up vote
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Since you know the coordinates of the vertices, you can ignore the angles. The coordinates of $vec v$ can be found as a proportion of the coordinates of the appropriate edge. For the illustrated case, $$vec v = {|vec v|over|A-C|}(A-C).$$
add a comment |
up vote
0
down vote
Since you know the coordinates of the vertices, you can ignore the angles. The coordinates of $vec v$ can be found as a proportion of the coordinates of the appropriate edge. For the illustrated case, $$vec v = {|vec v|over|A-C|}(A-C).$$
add a comment |
up vote
0
down vote
up vote
0
down vote
Since you know the coordinates of the vertices, you can ignore the angles. The coordinates of $vec v$ can be found as a proportion of the coordinates of the appropriate edge. For the illustrated case, $$vec v = {|vec v|over|A-C|}(A-C).$$
Since you know the coordinates of the vertices, you can ignore the angles. The coordinates of $vec v$ can be found as a proportion of the coordinates of the appropriate edge. For the illustrated case, $$vec v = {|vec v|over|A-C|}(A-C).$$
answered Nov 16 at 2:39
amd
28.5k21049
28.5k21049
add a comment |
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It's not possible as the orientation of the original triangle is not known. If you can rotate the figure in such a way that vector is parallel to axis $x$ or $y$, you solved your problem.
– Vasya
Nov 15 at 15:41